English

Unambiguous comparison of ensembles of quantum states

Quantum Physics 2008-12-11 v1

Abstract

We present a solution of the problem of the optimal unambiguous comparison of two ensembles of unknown quantum states (psi_1)^k and (psi_2)^l. We consider two cases: 1) The two unknown states psi_1 and psi_2 are arbitrary states of qudits. 2) Alternatively, they are coherent states of a harmonic oscillator. For the case of coherent states we propose a simple experimental realization of the optimal "comparison" machine composed of a finite number of beam-splitters and a single photodetector.

Keywords

Cite

@article{arxiv.0712.1616,
  title  = {Unambiguous comparison of ensembles of quantum states},
  author = {Michal Sedlak and Mario Ziman and Vladimir Buzek and Mark Hillery},
  journal= {arXiv preprint arXiv:0712.1616},
  year   = {2008}
}

Comments

7 pages, 3 figures